The invention provides the use of an antibody or antibody fragment which specifically binds a marker produced by or associated with a cell or tissue in an organ of interest, said antibody or antibody fragment being labelled with a radioisotope or with a magnetic resonance image enhancing agent capable of external detection, in the manufacture of a medicament for use in a method of imaging hypoplastic, anatomically displaced or ectopic cells or tissues in a mammalian subject by scintigraphic or magnetic resonance imaging, wherein the amount of the labelled antibody or antibody fragment is sufficient to permit a scintigraphic image or an enhanced magnetic resonance image of said organ to be obtained. Also provided is a kit for use in such methods.